Skip to main content

C is Not a Subset of C++

I came across an absurd article.

A well-written C program is a C++ program. Therefore, a well-written C program should be compilable with a C++ compiler.

This statement was undoubtedly true before 1999. Bjarne Stroustrup definitely took C compatibility into account when creating C++. At that time, well-written C code that adhered to the ANSI C standard was correctly compiled with a C++ compiler. However, that's limited to the time before the release of C99.

C99 introduced various new features, which C++ had already implemented differently or did not consider necessary. Moreover, the release of the new C11 standard and the new C++ standards(C++03, C++11, and more) have widened the gap between the two languages to a point where it is practically impossible to bridge.

Code that follows the C89 standard can still be compiled with a C++ compiler. But how many programs nowadays use C89? Try to find an actively developed project that uses C89. I have never tried to find one.

So, people who make such statements these days simply have not studied the topic properly. They might have learned it 20 years ago. When I told one such person that C++ and C specs have changed since C99 and that well-written C code that adheres to the C99 standard may not be compiled with a C++ compiler, the response I received was even more ridiculous.

The problem is not the standard; a well-written C program should be compilable with a C++ compiler. If the code cannot be compiled with a C++ compiler, it is not well-written C code.

Ah... it is truly shocking and absurd. He is misguided and overlooks the inherent differences between the two languages.

I cannot understand why one would look to C++ to define what well-written C code is. The two languages have already diverged. There was a time when Bjarne Stroustrup tried to merge C and C++, but he gave up on that idea. He even says that C/C++ is a term used by people who don't have a clue about programming. You should not use C/C++ to refer to C and C++, as they are no longer the same language. If you claim that only code that can be compiled with a C++ compiler is well-written C code, you are essentially giving up on all the features added to C since C99.

Let me clarify: well-written C code that adheres to the standard will not be compilable with a C++ compiler.

This article is a translation of a Korean post written in 2015. If you would like to view the original, please refer to this link.

Translating and revisiting it after 8 years, I feel a little better seeing that the term "C/C++" is used more infrequently than in the past since the establishment of modern C++.


Popular posts from this blog

[C++] Handling Exceptions in Constructors

When you use RAII idiom, there are often situations where constructors have to do complex tasks. These complex tasks can sometimes fail, resulting in throwing exceptions. This raises a concern: Is it okay to throw exceptions in constructors? The first concern is memory leaks. Fortunately, memory leaks do not occur. Variables created on the stack are released through stack unwinding, and if an exception occurs during heap allocation with the new operator, the new operator automatically deallocates the memory and returns nullptr . The next concern is whether the destructor of the member variables will be called correctly. However, this is also not a problem. When an exception occurs, member variables can be divided into three categories: fully initialized member variables, member variables being initialized, and uninitialized member variables. Fully initialized member variables have had their constructors called and memory allocations completed successfully. In the example code, t

Iterator Adapters in Rust

An Iterator that takes another iterator and returns a new one is called an iterator adapter . The name "adapter" comes from one of the GoF's design patterns, the adapter pattern . However, in reality, it corresponds more to the decorator pattern , so if you pay too much attention to the name, you might get confused about its purpose. So it's better not to worry too much about the name. Enough complaining about the name, what does an iterator adapter do? An iterator adapter adds a task to be performed when the iterator iterates. This will be easier to understand when you see an example. The map function is one of the famous adapters. The iterator returned by the map function for those who have used functional languages iterates over new values transformed from the original values. Besides, various adapters are already implemented in the standard library. Among them, the most frequently used are those that are convenient to use with loops. Examples include the

Clear Screen with CSI Sequence

Today, following my previous post , I will explain how to clear the screen using CSI Sequences. There are two sequences in the CSI Sequence for clearing. The first one is the Erase in Line sequence, called EL . It is composed of CSI # K ; it is used to erase lines, as the name suggests. If the # is not provided, the default value is 0, and if a value is provided, it must be one of the three: 0, 1, or 2. The terminal will ignore the sequence if any other value is provided. For example, if you print 0x311b5b334b32 (or 1^[3K2 ), the terminal ignores ^[3K , and the screen displays only 12 . The behavior of 0, 1, and 2 can be summarized as follows. 0 Erases from the cursor to the end of the line. 1 Erases from the beginning of the line to the cursor. 2 Erases the entire line, regardless of the cursor's position. Remember that the EL sequence does not move the cursor's position. Therefore, if you want to erase the current line and write a new line on the c